Basic tops in practically any colour would go with those shorts whether it be in black, white, grey, red, navy blue, light blue or yellow! When it gets a little chilly, you could pair it with a cost cardigan or even a blazer in black, pink, blue or green!

Do you have a photo of the shorts? or a link to a pair that looks similar.
Ballet flats would definitely go with them for a simple look. You could even wear slip on keds or canvas shoes depending on what the shorts look like and what top you wear. Almost any colour shoe would look good as the shorts are white. Oxfords would also be a nice choice too.